1. Field of the Invention
The present invention relates to bolt covers and, in particular, to a cover for the end of a bolt which also covers a nut attached thereto.
2. Description of the Invention Background
In various applications, a threaded bolt is screwedly engaged by a threaded nut such that a certain length of the bolt extends beyond the height of the nut. For example, a pole which supports an object such as a sign, light or traffic signal may be secured to the ground by means of anchor bolts. Anchor bolts are commonly formed of steel and are embedded in a concrete foundation. A base plate of the pole is provided with apertures which pass over the bolt and is secured by nuts which attach to the top portion of the anchor bolt. It will be readily appreciated that the connection of the pole to the ground in this manner is most important for the stability of the pole.
For various reasons, it is useful to provide some mechanism for covering the exposed end of a bolt such as those which may be employed to anchor a pole to the ground. A principal reason for providing a cover for the end of a bolt is safety. The upwardly extending end of an uncovered bolt could cause serious personal injury if one were to fall on to the bolt. Secondly, bolt covers are used to prevent corrosion of the bolt. The effect of normal corrosive action on an anchor bolt is known to lessen the diameter thereof thus weakening it and providing less stability to the overall structure. Finally, bolt covers are employed in order to improve the aesthetics of a bolt installation.
Heretofore, various types of anchor bolt covers have been proposed to address the above-indicated concerns. One previous means of covering anchor bolts is by the use of a steel or aluminum casting or a fabricated cover passing over the bolts and which may be attached to the pole or the base plate by a suitable fastening means such as screws. The problem with such covers is that additional holes must be drilled and tapped in the pole or the base plate to receive the screws. These holes must either be protected during the galvanizing or painting of the pole and, hence, its screw holes or the screw holes must be retapped after such operations. In addition, the fabrication and installation costs of such covers are considerable. Further, most previous fabricated anchor bolt covers extend from the anchor bolt to the pole. Of course, as the pole shaft size varies or the anchor bolt spacing varies, a variety of cover sizes are required. It will be appreciated, therefore, that fabricated anchor bolt covers are often unacceptably costly for various reasons.
Another type of bolt protector consists of a thread protector. A thread protector formed of a vinyl material may be of a relatively small thickness so that it may be molded by hand to the shape of the thread to be protected. Metal thread protectors normally must have an internal thread cut therein which is threaded onto the anchor bolt. Obviously, metal thread protectors are relatively expensive and easily removed by unthreading. In addition, neither of these forms of thread protectors are able to cover the nut as well as the end of the bolt.
A further type of bolt end protection consists of an acorn nut. An acorn nut is a nut which has an axial hemispherical body attached thereto. However, due to the provision of the hemispherical body, acorn nuts may only be applied a small distance along the length of the end of the bolt. The hemispherical portion prevents the application of the nut along greater lengths of the bolt. Additionally, acorn nuts must be obtained for each thread configuration involved and are also easily removed by unthreading.
The subject invention is directed toward an improved means for covering the end of a bolt and a nut attached thereto which overcomes, among others, the above-discussed problems and provides a secure, readily applied and inexpensive cover for the end of a bolt and an attached nut.